People with severe mental illness and co-occurring substance abuse disorder are at extremely high risk for HIV, hepatitis B, and hepatitis C. An estimated 1/2 of these dually diagnosed clients test positive for at least one infection, and co-infection, which complicates course and treatment of infection, is also high. Approximately 2/3rds of dually diagnosed clients with HIV are likely to be infected with HCV. Best-practice interventions for blood-borne infections, including screening, testing, immunizing, counseling, and referring to medical specialists could be life-saving for these clients, but they generally do not receive these services. We have developed and pilot tested a brief intervention (STIRR) to provide common basic preventive measures for blood-borne infections to patients with severe mental illness and substance use disorders. Community mental health systems, where clients are most reliably engaged, are not adequately providing these recommended services. The STIRR intervention is based on integrating mental health and other medical care through a public health approach, delivered by nursing and medical specialists, at the site of mental health care. We propose a randomized clinical trial to test STIRR against the usual service model, in which mental health practitioners refer patients directly to other medical providers off site. The proposed RCT will be conducted with an ethnically diverse, inner city sample of low-income clients receiving community based mental health care at two sites in Baltimore, MD, an area of high infection prevalence. Pilot data support the hypothesis that the intervention will prove feasible in typical community mental health settings serving high-risk clients. We hypothesize that clients who receive STIRR, compared to clients receiving treatment as usual, will be more likely to receive screening, testing, immunization, counseling for risk reduction, and appropriate medical care.